> Seagate is leveraging its heat-assisted magnetic recording (HAMR) technology to deliver its 6.9TB platter. If you want to check out how Seagate's HAMR technology works, check out our previous coverage. In a nutshell, HAMR uses heat-induced magnetic coercivity to write to a hard drive platter.<p>Wow so heat assisted magnetic recording is using heat to magnetically record data. Incredible explanation.
Heating a ferromagnetic material lowers it coercivity -- the heat softens it and makes it less magnetically "springy". And if heated enough it fully loses its magnetization.<p>So, to write, zap the area with a laser to heat it up. The coercivity is lowered. This lets a weaker magnetic field work to magnetize the area. This allows packing more densely, as the weak field will not affect the neighbouring cooler and higher coercivity regions.<p>(I think.)<p>This is not the first time lasers have been used to write to magnetic media. Magneto-optical discs (e.g. Sony's MiniDisc) were erased using laser heat. (MO discs also were read with laser, the ferromagnetic material used had different optical properties depending on magnetization.)
I guess you could say that MiniDisc was the original HAMR format.
Yeah, don't try to learn science from Tom's Hardware.
Mofo magnets! How do they work? With heat?!
I wonder what the lifespan, error rate and speed of these drives are
I just bought a 2tb SSD drive that's the size of a tictac container...
Sure. And you paid, what, maybe $120? so, $60/tb. When seagate commercializes these, it'll be around $10/tb. My last seagate spinning disks for my nas were 20tb for $150.<p>SSDs have a valuable place in the world, but so do spinning disks. Physical size isn't a concern for my nas (I mean, assuming we're talking < 300cm^3 for the whole setup..), but $/tb is.
Spinning rust still typically holds advantages for archival storage, as well.<p>There was literally a headline on the front page here a few days ago re: data degradation of SSDs during cold storage, as one example.
The article in question: "Unpowered SSDs slowly lose data" <a href="https://news.ycombinator.com/item?id=46038099">https://news.ycombinator.com/item?id=46038099</a>
I missed that earlier post to ask a question that always bugs me... do SSDs, when powered on, actually "patrol" their storage and rewrite cells that are fading even when quiescent from the host perspective?<p>Or does the data decay there as well, just as a function of time since cells were written?<p>In other words, is this whole focus on "powered off" just a proxy for "written once" versus "live data with presumed turnover"? Or do the cells really age more rapidly without power?
I was researching that topic a little bit a while ago but with no usable outcome. The aim was to find out how to cope with SSDs as backups. Is it enough to plug them into a power connection once in a while so the firmware starts the refresh cycle? Do I need to do something else? How often does it need to be plugged in? Thankful for any pointers ...
> <i>Data degradation of SSDs during cold storage</i><p>Why is that? I'd have expected solid-state electronics to last longer at low temperatures.<p>Or is it precisely that, some near/superconductivity effects causing naughty electrons to escape and wander about?
They mean powered off, not physically cold. Electrons escape the NAND flash over time and if the device is not active it's not refreshing them.
It's not super conductivity but instead quantum mechanics.<p>High capacity hard drives nowadays use heat and strong magnetic fields to write patterns into the platter. It's pretty stable just sitting around doing nothing.<p>High density multi level NAND involves quantum tunneling a few electrons using a strong electric field into an electrically insulated bit of semiconductor. Over some time the electrons tunnel their way out, but usually this only ends up actually happening if too much writing damaged the insulation.
By cold, I think they mean "powered off", not "low temperature".
Also far lower chance to lose your data on HDD if left in a shelf for 3 years
Where are you buying 20TB HDDs for $150?
“Disk is the new tape” has been true for a while and will probably stay true.<p>SSD also has longer term data loss issues when unpowered. Magnetic disk is still better in that respect too.
Flash is far denser than hard disks but as long as it's more expensive it's not that relevant.
>7TB to 15TB platters available from 2031 onward<p>Isn't 0.1TB a little too low? I'm sure if they only improved this little in 5 years the company would be in big trouble.
When we are getting the DNA storage we'll all been promised?
What is the theoretical limit of a standard-sized platter? ChatGPT thinks 50 TB max. Some forums say petabytes. Is there a known limit for it? I can't find much on the internet about the maximums.
A single iron atom can be a magnetic domain. So a surface coated with single-atom domains, spaced a few atoms apart. I would posit that's close to the 2D limit because of physics. They can't be directly next to each other or it's impossible to read or write them.<p>So very roughly, about 1 bit per square nanometre. Which unless I'm dropping an order of magnitude (very possible) is about 10 petabits per square centimetre, and with about 300 square centimetres for a 3.5" platter that's 3 exabits or so per side of platter.<p>Whether it will ever be possible to actually read or magnetize domains that small without interfering with the neighbouring domains is the question and no one knows. There have been several breakthroughs, like perpendicular recording, that have brought us much closer to the theoretical limit above, than anyone would have thought.
Practically we are nowhere close to the limit if you can record in 3d not just on the surface as all current drives so.
nice
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The perfect number.<p>The ideal has been achieved. We need go no further.